Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu sau » hieu suat, tieu su, hieu va
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
tai cua » thai cua, tai cuc, tri cua
cham lo » cham o, cam lo, cham soc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu su » tieu su, hieu so, hieu suat
hieu vu » hieu va, hieu ve, dieu vu
lo van » le van, vo van, so van
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang x hoi. ((hieu vu) or (((hieu su) OR (hieu sau)))) cham lo van hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang x hoi. ((hieu vu) OR (((hieu su) OR (hieu sau)))) cham lo van hanh tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang x hoi. ((hieu vu) or (((hieu su) OR (hieu sau)))) cham lo van hanh tai cua tre*".